title: Infant cortisol and behavioral habituation to weekly maternal separations: links with maternal prenatal cortisol and psychosocial stress.
abstract: BACKGROUND
  Our aim was to examine infants' behavioral and physiological stress responses to three weekly maternal separations, in relation to maternal prenatal psychosocial stress and cortisol. The hypothesis was that more prenatal stress and higher cortisol concentrations would predict smaller decreases in negative behavior and cortisol responses over the separations (i.e. less habituation).
  
  
  METHODS
  General and pregnancy-related feelings of stress and anxiety, as well as circadian cortisol levels, were measured in 107 mothers in the third trimester of pregnancy. At 9 months of age, infants were subjected to three weekly 1-h maternal separations in their homes. Salivary cortisol was obtained from the infants prior to the separation and at 35, 75, and 90 min after the mother had left. For each separation, the area under the curve to the ground (AUCg) was calculated to measure the infants' cortisol response, and the sum of the time spent crying and fussing was calculated to measure the infants' behavioral response.
  
  
  RESULTS
  Maternal pregnancy cortisol awakening response (CAR) significantly predicted infants' cortisol and behavioral responses. A lower CAR was related to a decreasing cortisol response, while a higher CAR was related to a stable cortisol response over all separations, as well as to less crying and fussing over all separations.
  
  
  CONCLUSIONS
  Increased maternal prenatal stress, as measured by the CAR, is related to altered behavioral and cortisol responses to a repeated stressor in the 9-month-old infant. These responses might result in prolonged periods with high cortisol levels that may affect the child's development.
authors.affiliation: Department of Developmental Psychology, Behavioural Science Institute, Radboud University Nijmegen, The Netherlands. Electronic address: c.deweerth@psych.ru.nl.
authors.forename: Carolina
authors.initials: C
authors.lastname: de Weerth
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
authors.forename: Roseriet
authors.initials: R
authors.lastname: Beijers
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001007:Anxiety / Q000523:psychology; D001010:Anxiety, Separation / Q000378:metabolism* / Q000523:psychology*; D019540:Area Under Curve; D003448:Crying; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007223:Infant; D018730:Infant Behavior; D007231:Infant, Newborn; D008426:Maternal Deprivation; D009035:Mothers; D009483:Neuropsychological Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000378:metabolism* / Q000523:psychology*; D055815:Young Adult
chemical_list: D006854:Hydrocortisone
keywords: Behavior; Cortisol; Cortisol awakening response (CAR); Crying; Habituation; Infancy; Maternal prenatal stress